**High dimensional input data**
If data dimension is much larger than the requested number of components * k*, linear PCA pre-processing of the data is recommended for reducing the dimension of the data before applying nonlinear PCA. This can automatically be done by using the option ' `pre_pca` '. **Example**data dimension: 20 (or larger) requested components: **k=3***The dimension of the input data will be reduced to ***12** by setting this number as required input (and output) units of the nonlinear network structure. `[pc,net,network]=nlpca(data,`**3**,** 'pre_pca','yes'**, 'units_per_layer',[**12**, 8, 3, 8, **12**] ); |